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Research Square (Research Square), Apr 17, 2024
Water Resources Management, 2022
Considering changes in irrigation planning and development due to climate change is necessary to ... more Considering changes in irrigation planning and development due to climate change is necessary to avoid system failure. This study demonstrated that changes in dependable flow and diversion water requirements in the future due to climate change will reduce potential irrigable areas. Climate change were based on the published projected climate in the study area. The dependable flow derived from successfully calibrated and validated Soil and Water Assessment Tool (SWAT) model streamflow simulations and the diversion water requirements based on the CROPWAT estimations of irrigation scheme were used to assess the potential irrigable areas. Substantial reductions in potential rice production areas (-4% to – 39%) were largely due to dwindled dependable flow (-1% to -25%) and an increase in diversion water requirement (+ 7% to + 26%). Reduction in potential irrigable area was projected during dry and normal years and may worsen towards the late twenty-first century under the worst-case climate scenario. Swelling of rivers during wet years will increase stream flows and potential irrigable areas but may also pose a danger of flooding. The development of water storage structures is necessary to reduce the adverse impacts of too much water during the wet years. Crop calendars should also be retrofitted to optimize the use of available rainfall during dry and normal years and climate-proof future irrigation systems. The results showed that it is necessary to incorporate climate change in irrigation planning and development. The methodologies described here could be used to climate-proof future irrigation systems in other areas in the Philippines and other countries.
Theoretical and Applied Climatology, 2021
The lack of sufficient rainfall data has been a common problem that hampers water resources plann... more The lack of sufficient rainfall data has been a common problem that hampers water resources planning in many developing countries with sparse weather monitoring networks. Satellite rainfall data requires validation to be considered adequate for any purpose it may serve. This study aimed to validate the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) ability to estimate monthly rainfall amounts and detect rainfall occurrences for various water resources planning over the four types of climate in the Philippines. It was validated using data from 68 rainfall stations. The results showed that CHIRPS performed best during the dry seasons, and its performance was well correlated with climate type. It was found that the best estimate of rainfall amount is in Climate Type I. The CHIRPS showed adequate performance in reproducing rainfall amount in Climate Types II and III. Its lowest performance was seen in Climate Type IV with 50% of the stations having adequate CHIRPS e...
Research Square (Research Square), Apr 17, 2024
Water Resources Management, 2022
Considering changes in irrigation planning and development due to climate change is necessary to ... more Considering changes in irrigation planning and development due to climate change is necessary to avoid system failure. This study demonstrated that changes in dependable flow and diversion water requirements in the future due to climate change will reduce potential irrigable areas. Climate change were based on the published projected climate in the study area. The dependable flow derived from successfully calibrated and validated Soil and Water Assessment Tool (SWAT) model streamflow simulations and the diversion water requirements based on the CROPWAT estimations of irrigation scheme were used to assess the potential irrigable areas. Substantial reductions in potential rice production areas (-4% to – 39%) were largely due to dwindled dependable flow (-1% to -25%) and an increase in diversion water requirement (+ 7% to + 26%). Reduction in potential irrigable area was projected during dry and normal years and may worsen towards the late twenty-first century under the worst-case climate scenario. Swelling of rivers during wet years will increase stream flows and potential irrigable areas but may also pose a danger of flooding. The development of water storage structures is necessary to reduce the adverse impacts of too much water during the wet years. Crop calendars should also be retrofitted to optimize the use of available rainfall during dry and normal years and climate-proof future irrigation systems. The results showed that it is necessary to incorporate climate change in irrigation planning and development. The methodologies described here could be used to climate-proof future irrigation systems in other areas in the Philippines and other countries.
Theoretical and Applied Climatology, 2021
The lack of sufficient rainfall data has been a common problem that hampers water resources plann... more The lack of sufficient rainfall data has been a common problem that hampers water resources planning in many developing countries with sparse weather monitoring networks. Satellite rainfall data requires validation to be considered adequate for any purpose it may serve. This study aimed to validate the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) ability to estimate monthly rainfall amounts and detect rainfall occurrences for various water resources planning over the four types of climate in the Philippines. It was validated using data from 68 rainfall stations. The results showed that CHIRPS performed best during the dry seasons, and its performance was well correlated with climate type. It was found that the best estimate of rainfall amount is in Climate Type I. The CHIRPS showed adequate performance in reproducing rainfall amount in Climate Types II and III. Its lowest performance was seen in Climate Type IV with 50% of the stations having adequate CHIRPS e...